3-D computational method of wave loads on turret moored FPSO tankers

A three-dimensional method of calculating wave loads of turret moored FPSO (Floating Production Storage and Offloading) tankers is presented. The linearized restoring forces acting on the ship hull by the mooring system are calculated according to the catenary theory, which are expressed as the function of linear stiffness coefficients and the displacements of the upper ends of mooring chains. The hydrodynamic coefficients of the ship are calculated by the three-dimensional potential flow theory of the linear hydrodynamic problem for ships with a low forward speed. The equations of ship motions are established with the effect of the restoring forces from the mooring system included as linear stiffness coefficients. The equations of motions are solved in frequency domain, and the responses of wave-induced motions and loads on the ship can be obtained. A computer program based on this method has been developed, and some calculation examples are illustrated. Analysis results show that the method can give satisfying prediction of wave loads.     

柴油机电子调速器可靠性设计

文章阐述了柴油机电子调速器可靠性质量指标的重要性，提出了可靠性设计是提高电子调速器可靠性的基础，并具体地介绍了柴油机电子调速器的可靠性设计，采用裕度设计，降额设计，保护电路设计和耐振设计等技术措施，多年的实际应用证明，其可靠性是能够得到了分保证的。     

TFJC-99型驼峰信号微机监测系统

ＴＦＪＣ－９９型驼峰信号微机监测系统的研制意义，监测范围，主要功能，总的结构设计。     

船载货物单元在非规则波中系固有效性校核的一种评价方法

货物单元在运输中,合理系固是确保船舶安全的重要因素,而系固方案制定后,如何针对实际海况对其系固效果进行正确评价则是货物系固的关键.在非规则波的基础上,充分考虑到各自由度运动之间的耦合影响,提出一种更为贴近海上实际的系固有效性校核的评价方法,同时将风力、波溅力、摩擦力等因素考虑到此方法当中,由此得出的结论会更客观.也为完善系固方案提供了依据,并可作为《货物积载和系固安全操作规则(CSS Code)》的补充.     

现场预制公路T形梁的外观质量控制

公路T形梁预制中,梁体漏浆、气泡、水纹严重影响外观质量。结合现场制梁的施工实践,简要分析了外观质量问题的产生原因,介绍了施工生产中采取的预防漏浆、气泡、水纹的控制措施。     

多相感应电机电磁场分析

本文采用ansys和ansoft软件进行多相感应电机短距和整距的电磁场分析,得出多相电机设计的有益结论,并通过试验验证电磁场计算的准确性.     

Wind pressure distribution and wind-induced dynamic response for spatial groined latticed vaults

The wind pressure distribution and wind-induced vibration responses of long-span spatial groined latticed vaults (SGLVs) were numerically simulated, which always are ones of the most important problems in the structural wind resistance design. Incompressible visco-fluid model was introduced, and the standard k-εtwo equation model and semi-implicit method for pressure linked equation (SIMPLE) were used to describe the flow turbulence. Furthermore, the structural dynamic equation was set up, which is solved by Newmark-β method. And several sort of wind-induced vibration coefficients such as the wind-induced vibration coefficient corresponding to the nodal displacement responses and wind loads were suggested. In the numerical simulation where the SGLV consisting of the cylindrical sectors with different curved surface was chosen as the example,the influence on the relative wind pressure distribution and structural wind-induced vibration responses of the closed or open SGLV caused by such parameters as the number of cylindrical sectors, structural curvature and the ratio of rise to span was investigated. Finally, some useful conclusions on the local wind pressure distribution on the structural surface and the wind-induced vibration coefficients of SGLV were developed.     

Improvement of the second order approximation of the smoothed particle hydrodynamics

The smoothed particle hydrodynamics (SPH), as a fully Lagrangian particle method, has been successfully applied to astrophysical problems and extended to elastic dynamics and computational fluid dynamics.High order derivatives have to be approximated when elastic dynamics problems are modeled. However, the approximation errors in SPH could lead to computational failure in the case that the order of derivative is high.A novel method was proposed in order to improve the accuracy of SPH method, which shows the relationship between the selected functions and their SPH approximations. The entire involved system was represented by a finite number of particles that carry individual mass and occupy individual space, and the integral interpolation was approximated by a summation interpolation. In addition, error comparison was made between SPH method with and without the present improvement.     

两种生产工艺机制砂掺配对混凝土性能的影响

本文针对湿法制砂得到的水洗砂和干法制砂得到的风吸砂掺配比例问题,分析了水洗砂和风吸砂的差异,研究了不同生产工艺机制砂掺配比例对铁路工程泵送混凝土工作性能、抗压强度、电通量和碳化性能的影响。结果表明:两种机制砂级配和压碎值相近,风吸砂略粗,石粉含量较低,水洗砂较干净,需水量比较低;随着水洗砂掺配比例的提高,混凝土减水剂掺量呈现降低的趋势,混凝土流动性得到改善,采用泵送施工工艺的情况下,推荐机制砂掺配比例水洗砂/风吸砂为7/3;随着水洗砂掺配比例的增加,混凝土抗压强度逐渐增大,电通量呈现降低趋势,抗碳化性能提高,主要原因是水洗砂掺配比例增加,混凝土密实性得到提高。研究工作能够推进机制砂混凝土应用,提高机制砂混凝土质量。     

山东半岛制造业基地技术引进战略与模式探讨

当前,世界制造业正加速由发达国家向发展中国家转移。面对机遇,如何制定有效的技术引进模式,有选择、有重点地引进先进技术,加快半岛制造业基地的建设,成为一个重要的战略问题。本文对山东半岛制造业基地技术引进的模式进行了探讨,并提出了相应的策略。